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Biology subjects

Luiselli, D.

Publications and source records attributed to Luiselli, D..

5 recordsLinked to original sources

Ecology and demographic structure of an extinct ibex population in Upper Palaeolithic Italian Alps

Alpine Upper Palaeolithic contexts exhibit specialised subsistence strategies, heavily dependent on Capra ibex. Among them, the rock shelter Riparo Dalmeri stands out, with C. Ibex dominating faunal remains across all occupation phases, spanning the Pleistocene/Holocene transition. This evidence positions Riparo Dalmeri as a key site for exploring the interdependence between human groups and C. ibex during one of the most critical climatic and cultural shifts in human evolution. Here, we present the first multidisciplinary study on Late Palaeolithic C. ibex teeth from Riparo Dalmeri, integrating direct radiocarbon dating, isotope (87Sr/86Sr, {delta}13C, {delta}18O), proteomic, and aDNA analyses. We generated the earliest aDNA sequences for C. ibex and contextual evidence on mobility, seasonality, and sex ratios. We found that most C. ibex were local to the area despite consistent human presence. They reveal significant dietary differences between sexes as well as increased seasonality at the Pleistocene-Holocene transition. Our results identify Riparo Dalmeri as an extinct branch of the ibex mtDNA phylogeny, offering unprecedented insights into ibex ecology and evolution that resonate with present-day issues on the conservation of this species in the face of climate change.

ecology↗

Convergent evolution of complex adaptive traits enabled human life at high altitudes

Convergent adaptations represent paradigmatic examples of the capacity of natural selection to influence organisms biology. However, the possibility to investigate genetic determinants underpinning convergent complex adaptive traits has been offered only recently by methods for inferring polygenic adaptations from genomic data. Relying on this approach, we demonstrate how high-altitude Andean human groups experienced pervasive selective events at angiogenic pathways, which resemble those previously attested for Himalayan populations despite partial convergence at the single-gene level was observed. This provides unprecedented evidence for the drivers of convergent evolution of enhanced blood perfusion in populations exposed to hypobaric hypoxia for thousands of years.

evolutionary biology↗

The genomic impact of European colonization of the Americas

The human genetic diversity of the Americas has been shaped by several events of gene flow that have continued since the Colonial Era and the Atlantic slave trade. Moreover, multiple waves of migration followed by local admixture occurred in the last two centuries, the impact of which has been largely unexplored.\n\nHere we compiled a genome-wide dataset of [~]12,000 individuals from twelve American countries and [~]6,000 individuals from worldwide populations and applied haplotype-based methods to investigate how historical movements from outside the New World affected i) the genetic structure, ii) the admixture profile, iii) the demographic history and iv) sex-biased gene-flow dynamics, of the Americas.\n\nWe revealed a high degree of complexity underlying the genetic contribution of European and African populations in North and South America, from both geographic and temporal perspectives, identifying previously unreported sources related to Italy, the Middle East and to specific regions of Africa.

genomics↗

Impact of non-LTR retrotransposons in the differentiation and evolution of Anatomically Modern Humans

Transposable Elements are biologically important components of eukaryote genomes. In particular, non-LTR retrotransposons (N-LTRrs) extensively shaped the human genome throughout evolution. In this study, we compared retrotransposon insertions differentially present in the genomes of Anatomically Modern Humans, Neanderthals, Denisovans and Chimpanzees, in order to assess the possible impact of retrotransposition in the differentiation of the human lineage. Briefly, we first identified species-specific N-LTRrs and established their distribution in present day human populations. These analyses shortlisted a group of N-LTRr insertions that were found exclusively in Anatomically Modern Humans. Notably, these insertions targeted genes more frequently than randomly expected and are associated with an increase in the number of transcriptional/splicing variants of those genes they inserted in. The analysis of the functionality of genes targeted by human-specific N-LTRr insertions seems to reflect phenotypic changes that occurred during human evolution. Furthermore, the expression of genes containing the most recent N-LTRr insertions is enriched in the brain, especially in undifferentiated neurons, and these genes associate in networks related to neuron maturation and migration. Additionally, we also identified candidate N-LTRr insertions that have likely produced new functional variants exclusive to modern humans, which show traces of positive selection and are now fixed in all present-day human populations. In sum, our results strongly suggest that N-LTRr impacted our differentiation as a species and have been a constant source of genomic variability all throughout the evolution of the human lineage.

genomics↗

The Tell-Tale Genome

Observable patterns of cultural variation are consistently intertwined with demic movements, cultural diffusion, and adaptation to different ecological contexts (Cavalli-Sforza and Feldman 1981; Boyd and Richerson 1985). The quantitative study of gene-culture co-evolution has focused in particular on the mechanisms responsible for change in frequency and attributes of cultural traits, on the spread of cultural information through demic and cultural diffusion, and on detecting relationships between genetic and cultural lineages. Here, for the first time, we make use of worldwide whole-genome sequences (Pagani et al. 2016) to assess the impact of demic diffusion on cultural diversity, focusing on the variability observed in folktale traditions (N=596) (Uther 2004) in Eurasia and Africa. We show that at small geographic scales (<=5000 km) there is a strong correlation between folktale and genomic distance when the effect of geography is corrected, while geographic distance has no independent effect on the distribution of folkloric narratives at the same spatial scale. This points to demic processes (i.e. population movement and replacement) as the main driver of folktale transmission at limited geographic ranges. The role of population movements becomes more apparent when regions characterized by episodes of directional expansions, such as the Neolithization of West Eurasia, are examined. Furthermore, we identify 89 individual tales which are likely to be predominantly transmitted through demic diffusion, and locate putative focal areas for a subset of them.

evolutionary biology↗